Linear particle accelerators



My 38, 96? H. LESQUTET ETAL LINEAR PARTICLE ACCELERTORS Filed Aug. lT, 196?.

INVENTORS H-LEBOUTET er RJEAN United States Patent @ffice 3,331,961 Patented July 18, 1967 s ciaims. (ci. 25o-41.9)

The present invention relates to linear accelerators for charged particles and, more particularly, to such accelerators in which the particles have velocities close to that of light and carry energies of relatively high level or value.

The present invention essentially consists of improvements realized with these accelerators, principally with a view toward facilitating the adjustment and control thereof.

Additionally, the present invention aims at rendering it possible for the same installation to simultaneously furnish a beam of high energy particles and one or more lower energy beams.

According to the present invention, a linear chargedparticle accelerator, which is composed of a number of rectilinear sections, dispose-d one behind the other, is characterized by the following arrangementsvand features taken alone or in combination:

(l) A magnetic particle separator, preferably having four deilecting magnets, is interposed between each pair of consecutive sections;

(2) the magnetic separators are provided with lateral bifurcations or' branches `which permit the injection thereat of an auxiliary particle beam upstream of each accelerator section and the extraction of this auxiliary beam downstream of the same section; and/ or (3) means are disposed in each separator for permitting the analysis and measurement of the intensity of the beams. v

Accordingly, it is an object of the present invention to provide a linear particle accelerator of the type described hereinabove which effectively remedies the limitations and shortcomings encountered with the prior art constructions.

It is another object of the present invention to provide a linear accelerator of greater versatility and usefulness notwithstanding the relatively simplev and inexpensive changes made therein as compared to the prior art constructions.

Still a further object of the present invention resides in the provision of a linear particle accelerator which greatly facilitates operating adjustments to be'made for proper operation thereof.

Another object of the present invention resides in the provision of a linear accelerator capable of simultaneously handling a plurality of beams of differing energy levels.

These and other objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein the single figure thereof illustrates very schematically only one example of realization according to the present invention.

Referring now to the drawing, and more particularly to the single figure thereof, reference numeral 1 designates therein one of the rectilinear sections of which any suitable desired number thereof constitute a high energy level linear particle accelerator. Section 1 is connected with the preceding accelerator section 1 by a magnetic separator comprising magnets 2, 3, 4 and 5, and to the nextfollowing section 1" by a similar separator comprising magnets 2', 3, 4 and 5.

The'magnetic separators are preferably of the type described in the U.S. Patent No. 3,031,596, is-sued in the name of H. P. Leboutet et al. on Apr. 24, 1962, and assigned to the same assignee as the present application. Reference is made, therefore, to this patent and particularly to FIGURE 3 thereof for the description of the separators utilized in the present arrangement.

However, these magnetic separators are completed in the present application by the addition of bifurcations or branches 6 and 6.

Such arrangement permits the injection into branch line 6 of an auxiliary particle beam of lower energy level than the main beam traversing the field of magnet 4, and the subsequent extraction of this auxiliary beam into the branch line 6' where the auxiliary beam separates from the main beam deflected by 'the magnet 2.

The arrangement according to the present invention additionally comprises, in each magnetic separator, beamanalyzing and intensity-measuring apparatus, indicated schematically in the single figure herein by reference numerals 7, 7 and 8, 8. These apparatus are, for example,

of the type described in the copending patent application Ser. No. 218,227, entitled Measuring Apparatus, filed by the same applicants on Aug. 17, 1962, now Patent No. 3,293,429, and assigned to the same assignee. Since, however, the exact realization and construction thereof forms no part of the present invention, but may be of any known conventional construction, a detailed description thereof is dispensed with herein.

Owing Yto the arrangements and measures described hereinabove, the adjustments and the control of the accelerator according to the present invention may be made, section'by section, with the aid of particle beams of low energy level; ln fact, once the adjustments have been made with relatively'low energy levels separately for all of the sections, the installation is also perfectly regulated ing to the presentinvention to supply for utilization onel or several beams of'relatively low or very low energy level, at the same time as the main beam of high energy of the' accelerator, which increases thepossibilities as well as protableness of the installation.

While we have shown and described herein one embodiment in accordance with the present invention, it is understood that the same is not limited thereto, but is susceptible of many changes and modifications within the spirit and scope of the present invention, and we, therefore, do not wish to be limited to the details shown and described herein, but intend to cover all such modifications and changes as are encompassed by the scope of the appended claims.

We claim:

1. A charged-particle linear accelerator, comprising at least three physically separated accelerator sections, a plurality of separating means for separating the particles of a relatively high energy level particle beam in accordance with their energy levels and operatively connecting adjoining sections, said separating means being operatively inserted into at least two successive separations between two accelerator sections, means for injecting a inserted into at least two successive separations between adjoining accelerator sections, means including a derivation duct forv injecting a relatively W energy level particle beam in a first one of said separating means, and means including a derivation duct for extracting said relatively low energy levelbeam from a second one of said separating means which is located downstream with respect to said rst separating means along the normal charged particle path.

3. A charged-particle linear accelerator, comprising a least three physically separated accelerator sections, a plu- `rality of separating means for separating the particles of a relatively high energy level particle beam in accordance with their energy levels and operatively connecting adjoining sections, said separating means being operatively inserted into at least two successive separations between two accelerator sections, means for injecting a relatively 10W energy level particle beam in a first one of said separating means, means fory extracting said .relatively low` energy level particle beam in a second one'of said separating means which is located downstream with respect to4 said rst separating means along the normal charged particle path, and detecting means operatively associated with said separating means for measuring the intensity of the charged particle beam moving through a respective separating means.

4. A charged particle linear accelerator, comprising at least .three physically separated accelerator sections, 'a plurality of separating means vfor the particles of a relatively high energy level particle beam in accordance With their energy levels operatively connecting adjoining sections, said separating means being operatively inserted into at least two successive separations between adjoining accelerator sections, means including a derivation duct forv injecting a relatively low energylevel particle beam in a iirst one of said separating means, means including a derivation duct for extracting said relatively low yenergy level beam from a second one of saidvseparating means which is located downstream with respect to said first separating means along .the normal charged particle path, and detecting means associated with at least one of said derivation ducts formeasuring the intensity of said relatively low energy level beam.

5. A charged-particle linear accelerator, comprising at least three physically separated accelerator sections, a plurality of separating means `'for separating the particles of a relatively high energy level particle beam in accordance with their energy levels and operatively connecting 4 adjoining sections, said separating means being operatively inserted into at least two separations between .two accelerator sections, means for injecting` `a relatively low energy level particle beam in a first one of said separating means, and means for extracting said relatively low energy level particle beam in a second one of said separating means which is located downstream with respect to said first separating means 'along the normal charged particle path.

6. In a charged particle linear accelerator having a plurality of substantially linear accelerator sections, separating means for separating the particles in accordance with their energy levels and operatively -connecting successive ones of said sections, and means for injecting a rst,.rel'a tively high energy levelbeam into` the accelerator, .the

improvement essentially consisting of means operatively associated with one of said separating means to enable injection of a relatively lower energy level particle beam,

and means operatively associated with another one ofsaid separating means located downstream, with respect to ksaid one separating means along the charged particle path vfor extracting said relatively lower energy level beam.

7. In a charged particle linear accelerator having a plurality of accelerator sections, separating means operable to separate the particles in accordance with their energy levels and operatively connecting successive ones of said sections, and means for injecting into said accelerator a first beam of charged particles, the improvement essentially consisting of means operativelyr associated wtih one of said separating means `for injecting `a second charged particle beam having yan energy level different from said iirst beam, and second means operatively associated with another separating means located downstreamv with respect to said one separating means along .ther

charged-particle path for extracting thereat exclusively said 'second beam.

8. In a charged particle linear accelerator, comprising a series of straight tubular sections and 'a plurality of- References Cited UNITED STATES PATENTS 2,957,985 10/1960 Brubaker 250--4l.9 2,979,635 4/1961 Burleigh 3l5-5.42 Xy 3,040,173 6/1962 Higatsberger S15- 5.42 X 3,209,269 f 9/1965 Julian et al 313-,-63 X HERMAN KARL SAALBACH, Primary Examiner.

GEORGE N. WESTBY, Examiner.

S. CHATMON, JR., Assistant Examiner. 

1. A CHARGED-PARTICLE LINEAR ACCELERATOR, COMPRISING AT LEAST THREE PHYSICALLY SEPARATED ACCELERATOR SECTIONS, A PLURALITY OF SEPARATING MEANS FOR SEPARATING THE PARTICLES OF A RELATIVELY HIGH ENERGY LEVEL PARTICLE BEAM IN ACCORDANCE WITH THEIR ENERGY LEVELS AND OPERATIVELY CONNECTING ADJOINING SECTIONS, SAID SEPARATING MEANS BEING OPERATIVELY INSERTED INTO AT LEAST TWO SUCCESSIVE SEPARATIONS BETWEEN TWO ACCELERATOR SECTIONS, MEANS FOR INJECTING A RELATIVELY LOW ENERGY LEVEL PARTICLE BEAM IN A FIRST ONE OF SAID SEPARATING MEANS, AND MEANS FOR EXTRACTING SAID RELATIVELY LOW ENERGY LEVEL PARTICLE BEAMS IN A SECOND ONE OF SAID SEPARATING MEANS WHICH IS LOCATED DOWNSTREAM WITH RESPECT TO SAID FIRST SEPARATING MEANS ALONG THE NORMAL CHARGED PARTICLE PATH. 